Defining RSTD report resolution and accuracy for RSTD-based 5G NR positioning

ABSTRACT

An apparatus for use in a UE includes processing circuitry coupled to a memory. To configure the UE for Reference Signal Time Difference (RSTD)-based 5G-NR positioning. The processing circuitry is to determine a first PRS BW associated with a first PRS received from a first gNB associated with a first cell. A second PRS BW is determined, which is associated with a second PRS received from a second gNB of a second cell. An RSTD report resolution is determined based on the first PRS BW and the second PRS BW. A receive (Rx) timing difference between the first cell and the second cell is measured based on reception times of the first PRS and the second PRS. The measured Rx timing difference is mapped into an RSTD report for transmission to the first gNB, based on the RSTD report resolution.

PRIORITY CLAIM

This application claims the benefit of priority to U.S. ProvisionalPatent Application Ser. No. 62/910,957, filed Oct. 4, 2019, and entitled“METHODS OF DEFINING RSTD REPORT RESOLUTION AND ACCURACY REQUIREMENT FORRSTD BASED 5G NR POSITIONING.” This provisional patent application isincorporated herein by reference in its entirety.

TECHNICAL FIELD

Aspects pertain to wireless communications. Some aspects relate towireless networks including 3GPP (Third Generation Partnership Project)networks, 3GPP LTE (Long Term Evolution) networks, 3GPP LTE-A (LTEAdvanced) networks, and fifth-generation (5G) networks including 5G newradio (NR) (or 5G-NR) networks and 5G-LTE networks such as 5G NRunlicensed spectrum (NR-U) networks. Other aspects are directed tosystems and methods for defining reference signal time difference (RSTD)report resolution and accuracy for RSTD-based 5G-NR device positioning.

BACKGROUND

Mobile communications have evolved significantly from early voicesystems to today's highly sophisticated integrated communicationplatform. With the increase in different types of devices communicatingwith various network devices, usage of 3GPP LTE systems has increased.The penetration of mobile devices (user equipment or UEs) in modernsociety has continued to drive demand for a wide variety of networkeddevices in many disparate environments. Fifth-generation (5G) wirelesssystems are forthcoming and are expected to enable even greater speed,connectivity, and usability. Next generation 5G networks (or NRnetworks) are expected to increase throughput, coverage, and robustnessand reduce latency and operational and capital expenditures. 5G-NRnetworks will continue to evolve based on 3GPP LTE-Advanced withadditional potential new radio access technologies (RATs) to enrichpeople's lives with seamless wireless connectivity solutions deliveringfast, rich content and services. As current cellular network frequencyis saturated, higher frequencies, such as millimeter wave (mmWave)frequency, can be beneficial due to their high bandwidth.

Potential LTE operation in the unlicensed spectrum includes (and is notlimited to) the LTE operation in the unlicensed spectrum via dualconnectivity (DC), or DC-based LAA, and the standalone LTE system in theunlicensed spectrum, according to which LTE-based technology solelyoperates in the unlicensed spectrum without requiring an “anchor” in thelicensed to spectrum, called MulteFire. MulteFire combines theperformance benefits of LTE technology with the simplicity of Wi-Fi-likedeployments.

Further enhanced operation of LTE systems in the licensed as well asunlicensed spectrum is expected in future releases and 5G systems. Suchenhanced operations can include techniques for defining RSTD reportresolution and accuracy for RSTD-based 5G-NR device positioning.

BRIEF DESCRIPTION OF THE FIGURES

In the figures, which are not necessarily drawn to scale, like numeralsmay describe similar components in different views. Like numerals havingdifferent letter suffixes may represent different instances of similarcomponents. The figures illustrate generally, by way of example, but notby way of limitation, various aspects discussed in the present document.

FIG. 1A illustrates an architecture of a network, in accordance withsome aspects.

FIG. 1B and FIG. 1C illustrate a non-roaming 5G system architecture inaccordance with some aspects.

FIG. 2 illustrates a flow diagram of a method for RSTD report resolutionselection and mapping of RSTD into an RSTD report metric based on theRSTD report resolution, in accordance with some embodiments.

FIG. 3 illustrates a block diagram of a communication device such as anevolved Node-B (eNB), a new generation Node-B (gNB), an access point(AP), a wireless station (STA), a mobile station (MS), or a userequipment (UE), in accordance with some aspects.

DETAILED DESCRIPTION

The following description and the drawings sufficiently illustrateaspects to enable those skilled in the art to practice them. Otheraspects may incorporate structural, logical, electrical, process, andother changes. Portions and features of some aspects may be included inor substituted for, those of other aspects. Aspects outlined in theclaims encompass all available equivalents of those claims.

FIG. 1A illustrates an architecture of a network in accordance with someaspects. The network 140A is shown to include user equipment (UE) 101and UE 102. The UEs 101 and 102 are illustrated as smartphones (e.g.,handheld touchscreen mobile computing devices connectable to one or morecellular networks) but may also include any mobile or non-mobilecomputing device, such as Personal Data Assistants (PDAs), pagers,laptop computers, desktop computers, wireless handsets, drones, or anyother computing device including a wired and/or wireless communicationsinterface. The UEs 101 and 102 can be collectively referred to herein asUE 101, and UE 101 can be used to perform one or more of the techniquesdisclosed herein.

Any of the radio links described herein (e.g., as used in the network140A or any other illustrated network) may operate according to anyexemplary radio communication technology and/or standard.

LTE and LTE-Advanced are standards for wireless communications ofhigh-speed data for UE such as mobile telephones. In LTE-Advanced andvarious wireless systems, carrier aggregation is a technology accordingto which multiple carrier signals operating on different frequencies maybe used to carry communications for a single UE, thus increasing thebandwidth available to a single device. In some aspects, carrieraggregation may be used where one or more component carriers operate onunlicensed frequencies.

Aspects described herein can be used in the context of any spectrummanagement scheme including, for example, dedicated licensed spectrum,unlicensed spectrum, (licensed) shared spectrum (such as Licensed SharedAccess (LSA) in 2.3-2.4 GHz, 3.4-3.6 GHz, 3.6-3.8 GHz, and furtherfrequencies and Spectrum Access System (SAS) in 3.55-3.7 GHz and furtherfrequencies).

Aspects described herein can also be applied to different Single Carrieror OFDM flavors (CP-OFDM, SC-FDMA, SC-OFDM, filter bank-basedmulticarrier (FBMC), OFDMA, etc.) and in particular 3GPP NR (New Radio)by allocating the OFDM carrier data bit vectors to the correspondingsymbol resources.

In some aspects, any of the UEs 101 and 102 can comprise anInternet-of-Tings (IoT) UE or a Cellular IoT (CIoT) UE, which cancomprise a network access layer designed for low-power IoT applicationsutilizing short-lived UE connections. In some aspects, any of the UEs101 and 102 can include a narrowband (NB) IoT UE (e.g., such as anenhanced NB-IoT (eNB-IoT) UE and Further Enhanced (FeNB-IoT) UE). An IoTUE can utilize technologies such as machine-to-machine (M2M) ormachine-type communications (MTC) for exchanging data with an MTC serveror device via a public land mobile network (PLMN), Proximity-BasedService (ProSe) or device-to-device (D2D) communication, sensornetworks, or IoT networks. The M2M or MTC exchange of data may be amachine-initiated exchange of data. An IoT network includesinterconnecting IoT UEs, which may include uniquely identifiableembedded computing devices (within the Internet infrastructure), withshort-lived connections. The IoT UEs may execute background applications(e.g., keep-alive messages, status updates, etc.) to facilitate theconnections of the IoT network.

In some aspects, any of the UEs 101 and 102 can include enhanced MTC(eMTC) UEs or further enhanced MTC (FeMTC) UEs.

The UEs 101 and 102 may be configured to connect, e.g., communicativelycouple, with a radio access network (RAN) 110. The RAN 110 may be, forexample, an Evolved Universal Mobile Telecommunications System (UMTS)Terrestrial Radio Access Network (E-UTRAN), a NextGen RAN (NG RAN), orsome other type of RAN. The UEs 101 and 102 utilize connections 103 and104, respectively, each of which comprises a physical communicationsinterface or layer (discussed in further detail below); in this example,the connections 103 and 104 are illustrated as an air interface toenable communicative coupling and can be consistent with cellularcommunications protocols, such as a Global System for MobileCommunications (GSM) protocol, a code-division multiple access (CDMA)network protocol, a Push-to-Talk (PTT) protocol, a PTT over Cellular(POC) protocol, a Universal Mobile Telecommunications System (UMTS)protocol, a 3GPP Long Term Evolution (LTE) protocol, a fifth-generation(5G) protocol, a New Radio (NR) protocol, and the like.

In an aspect, the UEs 101 and 102 may further directly exchangecommunication data via a ProSe interface 105. The ProSe interface 105may alternatively be referred to as a sidelink interface comprising oneor more logical channels, including but not limited to a PhysicalSidelink Control Channel (PSCCH), a Physical Sidelink Shared Channel(PSSCH), a Physical Sidelink Discovery Channel (PSDCH), and a PhysicalSidelink Broadcast Channel (PSBCH).

The UE 102 is shown to be configured to access an access point (AP) 106via connection 107. The connection 107 can comprise a local wirelessconnection, such as, for example, a connection consistent with any IEEE802.11 protocol, according to which the AP 106 can comprise a wirelessfidelity (WiFi®) router. In this example, the AP 106 is shown to beconnected to the Internet without connecting to the core network of thewireless system (described in further detail below).

The RAN 110 can include one or more access nodes that enable theconnections 103 and 104. These access nodes (ANs) can be referred to asbase stations (BSs), NodeBs, evolved NodeBs (eNBs), Next GenerationNodeBs (gNBs), RAN nodes, and the like, and can comprise ground stations(e.g., terrestrial access points) or satellite stations providingcoverage within a geographic area (e.g., a cell). In some aspects, thecommunication nodes 111 and 112 can be transmission/reception points(TRPs). In instances when the communication nodes 111 and 112 are NodeBs(e.g., eNBs or gNBs), one or more TRPs can function within thecommunication cell of the NodeBs. The RAN 110 may include one or moreRAN nodes for providing macrocells, e.g., macro RAN node 111, and one ormore RAN nodes for providing femtocells or picocells (e.g., cells havingsmaller coverage areas, smaller user capacity, or higher bandwidthcompared to macrocells), e.g., low power (LP) RAN node 112.

Any of the RAN nodes 111 and 112 can terminate the air interfaceprotocol and can be the first point of contact for the UEs 101 and 102.In some aspects, any of the RAN nodes 111 and 112 can fulfill variouslogical functions for the RAN 110 including, but not limited to, radionetwork controller (RNC) functions such as radio bearer management,uplink and downlink dynamic radio resource management, and data packetscheduling, and mobility management. In an example, any of the nodes 111and/or 112 can be a new generation Node-B (gNB), an evolved node-B(eNB), or another type of RAN node.

The RAN 110 is shown to be communicatively coupled to a core network(CN) 120 via an S1 interface 113. In aspects, the CN 120 may be anevolved packet core (EPC) network, a NextGen Packet Core (NPC) network,or some other type of CN (e.g., as illustrated in reference to FIGS.1B-1C). In this aspect, the S1 interface 113 is split into two parts:the S1-U interface 114, which carries traffic data between the RAN nodes111 and 112 and the serving gateway (S-GW) 122, and the S-mobilitymanagement entity (MME) interface 115, which is a signaling interfacebetween the RAN nodes 111 and 112 and MMEs 121.

In this aspect, the CN 120 comprises the MMEs 121, the S-GW 122, thePacket Data Network (PDN) Gateway (P-GW) 123, and a home subscriberserver (HSS) 124. The MMEs 121 may be similar in function to the controlplane of legacy Serving General Packet Radio Service (GPRS) SupportNodes (SGSN). The MMEs 121 may manage mobility aspects in access such asgateway selection and tracking area list management. The HSS 124 maycomprise a database for network users, including subscription-relatedinformation to support the network entities' handling of communicationsessions. The CN 120 may comprise one or several HSSs 124, depending onthe number of mobile subscribers, on the capacity of the equipment, onthe organization of the network, etc. For example, the HSS 124 canprovide support for routing/roaming, authentication, authorization,naming/addressing resolution, location dependencies, etc.

The S-GW 122 may terminate the S1 interface 113 towards the RAN 110, androutes data packets between the RAN 110 and the CN 120. In addition, theS-GW 122 may be a local mobility anchor point for inter-RAN nodehandovers and also may provide an anchor for inter-3GPP mobility. Otherresponsibilities of the S-GW 122 may include a lawful intercept,charging, and some policy enforcement.

The P-GW 123 may terminate an SGi interface toward a PDN. The P-GW 123may route data packets between the EPC network 120 and external networkssuch as a network including the application server 184 (alternativelyreferred to as application function (AF)) via an Internet Protocol (IP)interface 125. The P-GW 123 can also communicate data to other externalnetworks 131A, which can include the Internet, IP multimedia subsystem(IPS) network, and other networks. Generally, the application server 184may be an element offering applications that use IP bearer resourceswith the core network (e.g., UMTS Packet Services (PS) domain, LTE PSdata services, etc.). In this aspect, the P-GW 123 is shown to becommunicatively coupled to an application server 184 via an IP interface125. The application server 184 can also be configured to support one ormore communication services (e.g., Voice-over-Internet Protocol (VoIP)sessions, PTT sessions, group communication sessions, social networkingservices, etc.) for the UEs 101 and 102 via the CN 120.

The P-GW 123 may further be a node for policy enforcement and chargingdata collection. Policy and Charging Rules Function (PCRF) 126 is thepolicy and charging control element of the CN 120. In a non-roamingscenario, in some aspects, there may be a single PCRF in the Home PublicLand Mobile Network (HPLMN) associated with a UE's Internet ProtocolConnectivity Access Network (IP-CAN) session. In a roaming scenario witha local breakout of traffic, there may be two PCRFs associated with aUE's IP-CAN session: a Home PCRF (H-PCRF) within an HPLMN and a VisitedPCRF (V-PCRF) within a Visited Public Land Mobile Network (VPLMN). ThePCRF 126 may be communicatively coupled to the application server 184via the P-GW 123.

In some aspects, the communication network 140A can be an IoT network ora 5G network, including a 5G new radio network using communications inthe licensed (5G NR) and the unlicensed (5G NR-U) spectrum. One of thecurrent enablers of IoT is the narrowband-IoT (NB-IoT).

An NG system architecture can include the RAN 110 and a 5G network core(5GC) 120. The NG-RAN 110 can include a plurality of nodes, such as gNBsand NG-eNBs. The core network 120 (e.g., a 5G core network or 5GC) caninclude an access and mobility function (AMF) and/or a user planefunction (UPF). The AMF and the UPF can be communicatively coupled tothe gNBs and the NG-eNBs via NG interfaces. More specifically, in someaspects, the gNBs and the NG-eNBs can be connected to the AMF by NG-Cinterfaces, and to the UPF by NG-U interfaces. The gNBs and the NG-eNBscan be coupled to each other via Xn interfaces.

In some aspects, the NG system architecture can use reference pointsbetween various nodes as provided by 3GPP Technical Specification (TS)23.501 (e.g., V15.4.0, 2018-12). In some aspects, each of the gNBs andthe NG-eNBs can be implemented as a base station, a mobile edge server,a small cell, a home eNB, and so forth. In some aspects, a gNB can be amaster node (MN) and NG-eNB can be a secondary node (SN) in a 5Garchitecture.

FIG. 1B illustrates a non-roaming 5G system architecture in accordancewith some aspects. Referring to FIG. 1B, there is illustrated a 5Gsystem architecture 140B in a reference point representation. Morespecifically, UE 102 can be in communication with RAN 110 as well as oneor more other 5G core (5GC) network entities. The 5G system architecture140B includes a plurality of network functions (NFs), such as access andmobility management function (AMF) 132, session management function(SMF) 136, policy control function (PCF) 148, application function (AF)150, user plane function (UPF) 134, network slice selection function(NSSF) 142, authentication server function (AUSF) 144, and unified datamanagement (UDM)/home subscriber server (HSS) 146. The UPF 134 canprovide a connection to a data network (DN) 152, which can include, forexample, operator services, Internet access, or third-party services.The AMF 132 can be used to manage access control and mobility and canalso include network slice selection functionality. The SMF 136 can beconfigured to set up and manage various sessions according to networkpolicy. The UPF 134 can be deployed in one or more configurationsaccording to the desired service type. The PCF 148 can be configured toprovide a policy framework using network slicing, mobility management,and roaming (similar to PCRF in a 4G communication system). The UDM canbe configured to store subscriber profiles and data (similar to an HSSin a 4G communication system).

In some aspects, the 5G system architecture 140B includes an IPmultimedia subsystem (IMS) 168B as well as a plurality of IP multimediacore network subsystem entities, such as call session control functions(CSCFs). More specifically, the IMS 168B includes a CSCF, which can actas a proxy CSCF (P-CSCF) 162BE, a serving CSCF (S-CSCF) 164B, anemergency CSCF (E-CSCF) (not illustrated in FIG. 1B), or interrogatingCSCF (I-CSCF) 166B. The P-CSCF 162B can be configured to be the firstcontact point for the UE 102 within the IM subsystem (IMS) 168B. TheS-CSCF 164B can be configured to handle the session states in thenetwork, and the E-CSCF can be configured to handle certain aspects ofemergency sessions such as routing an emergency request to the correctemergency center or PSAP. The I-CSCF 166B can be configured to functionas the contact point within an operator's network for all IMSconnections destined to a subscriber of that network operator, or aroaming subscriber currently located within that network operator'sservice area. In some aspects, the I-CSCF 166B can be connected toanother IP multimedia network 170E, e.g. an IMS operated by a differentnetwork operator.

In some aspects, the UDM/HSS 146 can be coupled to an application server160E, which can include a telephony application server (TAS) or anotherapplication server (AS). The AS 160B can be coupled to the IMS 168B viathe S-CSCF 164B or the I-CSCF 166B.

A reference point representation shows that interaction can existbetween corresponding NF services. For example, FIG. 1B illustrates thefollowing reference points: N1 (between the UE 102 and the AMF 132), N2(between the RAN 110 and the AMF 132). N3 (between the RAN 110 and theUPF 134), N4 (between the SMF 136 and the UPF 134), N5 (between the PCF148 and the AF 150, not shown), N6 (between the UPF 134 and the DN 152).N7 (between the SMF 136 and the PCF 148, not shown), N8 (between the UDM146 and the AMF 132, not shown), N9 (between two UPFs 134, not shown),N10 (between the UDM 146 and the SMF 136, not shown), N11 (between theAMF 132 and the SMF 136, not shown), N12 (between the AUSF 144 and theAMF 132, not shown), N13 (between the AUSF 144 and the UDM 146, notshown), N14 (between two AMFs 132, not shown), N15 (between the PCF 148and the AMF 132 in case of a non-roaming scenario, or between the PCF148 and a visited network and AMF 132 in case of a roaming scenario, notshown), N16 (between two SMFs, not shown), and N22 (between AMF 132 andNSSF 142, not shown). Other reference point representations not shown inFIG. 1E can also be used.

FIG. 1C illustrates a 5G system architecture 140C and a service-basedrepresentation. In addition to the network entities illustrated in FIG.1B, system architecture 140C can also include a network exposurefunction (NEF) 154 and a network repository function (NRF) 156. In someaspects, 5G system architectures can be service-based and interactionbetween network functions can be represented by correspondingpoint-to-point reference points Ni or as service-based interfaces.

In some aspects, as illustrated in FIG. 1C, service-basedrepresentations can be used to represent network functions within thecontrol plane that enable other authorized network functions to accesstheir services. In this regard, 5G system architecture 140C can includethe following service-based interfaces: Namf 158H (a service-basedinterface exhibited by the AMF 132), Nsmf 158I (a service-basedinterface exhibited by the SMF 136), Nnef 158B (a service-basedinterface exhibited by the NEF 154), Npcf 158D (a service-basedinterface exhibited by the PCF 148), a Nudm 158E (a service-basedinterface exhibited by the UDM 146), Naf 158F (a service-based interfaceexhibited by the AF 150), Nnrf 158C (a service-based interface exhibitedby the NRF 156), Nnssf 158A (a service-based interface exhibited by theNSSF 142), Nausf 158G (a service-based interface exhibited by the AUSF144). Other service-based interfaces (e.g., Nudr, N5g-eir, and Nudsf)not shown in FIG. 1C can also be used.

In example embodiments, any of the UEs or base stations discussed inconnection with FIG. 1A-FIG. 1C can be configured to operate using thetechniques discussed in connection with FIG. 2 and FIG. 3 .

Cellular technology-based UE positioning may be based onmulti-lateration techniques where the serving base station estimates theUE location, based on UE-reported measurements on the downlink referencesignal (DL RS) (e.g., timing, angle, cell ID, etc.), and/or based ondirect measurement of UE transmitted uplink reference signals (UL RS),which are received by the base stations. For 3GPP design, 4G LTE basedpositioning technology has been developed since Release 9, while 5G NRbased positioning technology is currently under development for Release16. For downlink (DL) based positioning methods, one key method whichmay be used is Observed Time Difference of Arrival (OTDOA), which isfurther based on Reference Signal Time Difference (RSTD) measurementsreported from the UE side. For RSTD measurements, the UE may estimatethe received timing differences of different base stations, based on thereceived downlink positioning reference signals (DL PRSs) from differentbase stations, and then report the RSTD results to the serving basestation.

Currently, the RSTD accuracy requirements and RSTD report resolution for5G NR are to be defined by RAN4 for Release 16. Techniques discussedherein may be used to optimize the definition of RSTD measurementaccuracy requirements as well as the RSTD report resolution, to optimizethe trade-off between UE complexity and NR positioning performance.

In some NR-related aspects, the RSTD measurement is based on NR PRS. ForLTE PRS, the PRS bandwidth is the same as the system bandwidth of an LTEcell, with fixed sub-carrier-spacing (SCS) and fixed reference resourceelement (RE) number. For NR PRS, however, the SCS, the reference REnumber, as well as the PRS BW for NR PRS can be flexibly configured. Tooptimize the trade-off between UE complexity and NR positioningperformance, the disclosed techniques can be used to adapt the RSTDreport resolution as well as accuracy measurement requirements based onthe flexible PRS configurations.

In some embodiments, the disclosed techniques include adapting the RSTDreport resolution based on the allocation bandwidth of the PRSs, whichare used for RSTD measurement. As for one example, the RSTD reportresolution could be directly selected between a reference timing unit Tsand a minimal timing unit Tc, in the following form:

$\begin{matrix}{{{RSTD}\mspace{14mu}{report}\mspace{14mu}{resolution}} = \left\{ \begin{matrix}{{Ts},{{{if}\mspace{14mu}{PRS}_{BW}} \leq {Th}}} \\{{k*{Tc}},{{{if}\ {PR}S_{BW}} > {Th}}}\end{matrix} \right.} & (1)\end{matrix}$

In the above formula (1), Th is a predefined threshold and an examplevalue could be 20 MHz. In some embodiments, separate thresholds may beused for Ts and Tc. In some embodiments, the RSTD report resolution maybe determined by the base station and communicated to the UE viaconfiguration signaling.

In the above formula (1), Ts is the legacy LTE RSTD resolution, which isalso the reference time unit for the reference numerology. In someembodiments, Ts can be computed in the following form:T _(s)=1/(Δf _(ref) ·N _(f,ref))=32.5 ns, wherein Δf _(ref)=15·10³ Hz,N_(f,ref)=2048.  (2)

In the above formula (1), Tc is the finest timing resolution that can beachieved by NR. In some embodiments, Tc can be computed in the followingform:T _(c)=1/(Δf _(max) ·N _(f))=0.5 ns, wherein Δf max=480·10³ Hz,Nf=4096,and k is an integer greater than 1.  (3)

In some embodiments, when an RSTD value is determined based on two PRSsfrom different cells with different PRS BW, the smaller PRS BW may beselected to further determine the RSTD report resolution. FIG. 2illustrates a flow diagram of a method 200 for RSTD report resolutionselection and mapping of RSTD into an RSTD report metric based on theRSTD report resolution, in accordance with some embodiments. Referringto FIG. 2 , at operation 202, a first positioning reference signal (PRS)bandwidth (BW) associated with the first PRS received from the firstNext Generation Node-B (gNB) is determined. The first gNB is associatedwith a first cell. At operation 204, a second PRS BW associated with asecond PRS received from a second gNB is determined. The second gNB isassociated with a second cell. At operation 206, an RSTD reportresolution is determined based on the first PRS BW and the second PRSBW. For example, the smaller of the first and second PRS BW may beselected as a minimal PRS BW. For example, the RSTD report resolution isselected based on the formula (1) above. In some embodiments, the RSTDreport resolution is determined by the gNB and is communicated to the UEvia configuration signaling. At operation 208, a receive (Rx) timingdifference between the first cell and the second cell is measured basedon reception times of the first PRS and the second PRS. At operation210, the measured Rx timing difference is mapped into an RSTD report fortransmission to the first gNB, based on the RSTD report resolution.

In some embodiments, the disclosed techniques may include adapting themaximal allowed RSTD errors based on the PRS BW, such that a higher RSTDerror margin could be defined for PRS with smaller BW while lower RSTDerror margin could be defined for PRS with higher BW.

In some embodiments, the disclosed techniques may include adapting thesignal-to-noise ratio (SNR) side condition for RSTD accuracy requirementbased on the total number of reference REs within a PRS symbol, suchthat the SNR side condition is tightened for PRS with a higher number ofref. REs, while the SNR side condition is relaxed for PRS with a lowernumber of ref. REs.

In some embodiments, the disclosed techniques may include performing anexact calculation to determine the RSTD report resolution. In someaspects, for a given PRS bandwidth, the corresponding RSTD resolutioncould be linearly scaled from the highest possible resolution (e.g.,with regard to the highest PRS BW) by the actual PRS bandwidth. That isbecause the DL PRS bandwidth is expected to be configurable up to maxchannel bandwidth. Therefore, the minimum reporting granularity may be afraction of T_(c)/2 and it may be scaled inversely proportionally to theDL PRS bandwidth used by UE for DL PRS processing. In some aspects, thefollowing expression may be used to determine the granularity of RSTDreporting:

$\begin{matrix}{{{{RSTD}\mspace{14mu}{report}\mspace{14mu}{resolution}} = {\left( \frac{400\mspace{14mu}{MHz}}{{BW}_{PRS}} \right) \cdot \frac{T_{c}}{2}}},{{{where}\mspace{14mu}{Tc}} = {0.5\mspace{14mu}{{ns}.}}}} & (4)\end{matrix}$

In some embodiments, the scaling factor of ½ could be skipped, such thatthe following expression can also be used to determine the granularityof RSTD reporting:

$\begin{matrix}{{{{RSTD}\mspace{14mu}{report}\mspace{14mu}{resolution}} = {\left( \frac{400\mspace{14mu}{MHz}}{{BW}_{PRS}} \right) \cdot T_{c}}},{{{where}\mspace{14mu}{Tc}} = {0.5\mspace{14mu}{{ns}.}}}} & (5)\end{matrix}$

In some embodiments, in both formula (4) and formula (5), Tc=0.5 ns andBW_(PRS) is the channel BW in MHz selected from the set [5, 10, 20, 25,40, 50, 80, 100, 200, 400] MHz and closest to the bandwidth of DL PRSreceive processing.

In some embodiments, a method is disclosed that user equipment (UE)receives at least two positioning reference signals, from two differentbase stations, and reports a reference signal reference received timingdifference (RSTD) between the two base stations, based on the receivedPRSs. The resolution of the reported RSTD is determined by the actualbandwidths of the PRSs. In some embodiments, the RSTD report resolutionis set to be a reference timing unit, Ts, if the PRS BW is below apre-defined threshold. In some embodiments, the RSTD report resolutionis set to be minimal timing unit, Tc, if the PRS BW is higher than apre-defined threshold. In some embodiments, the PRS BW, which is usedfor RSTD report resolution selection, is the minimal BW of the BWs ofthe measured PRS signals. In some embodiments, the measurement accuracyrequirements of the reported RSTD are determined based on the bandwidthsof the PRS, which are used for RSTD measurement. In some embodiments,the SNR side conditions for RSTD measurement accuracy requirements aredetermined based on the total number of reference resource elements(ref. REs) of the PRS, which is used for RSTD measurement.

FIG. 3 illustrates a block diagram of a communication device such as anevolved Node-B (eNB), a next generation Node-B (gNB), an access point(AP), a wireless station (STA), a mobile station (MS), or user equipment(UE), in accordance with some aspects and to perform one or more of thetechniques disclosed herein. In alternative aspects, the communicationdevice 300 may operate as a standalone device or may be connected (e.g.,networked) to other communication devices.

Circuitry (e.g., processing circuitry) is a collection of circuitsimplemented in tangible entities of the device 300 that include hardware(e.g., simple circuits, gates, logic, etc.). Circuitry membership may beflexible over time. Circuitries include members that may, alone or incombination, perform specified operations when operating. In an example,the hardware of the circuitry may be immutably designed to carry out aspecific operation (e.g., hardwired). In an example, the hardware of thecircuitry may include variably connected physical components (e.g.,execution units, transistors, simple circuits, etc.) including amachine-readable medium physically modified (e.g., magnetically,electrically, moveable placement of invariant massed particles, etc.) toencode instructions of the specific operation.

In connecting the physical components, the underlying electricalproperties of a hardware constituent are changed, for example, from aninsulator to a conductor or vice versa. The instructions enable embeddedhardware (e.g., the execution units or a loading mechanism) to createmembers of the circuitry in hardware via the variable connections tocarry out portions of the specific operation when in operation.Accordingly, in an example, the machine-readable medium elements arepart of the circuitry or are communicatively coupled to the othercomponents of the circuitry when the device is operating. In an example,any of the physical components may be used in more than one member ofmore than one circuitry. For example, under operation, execution unitsmay be used in a first circuit of a first circuitry at one point in timeand reused by a second circuit in the first circuitry, or by a thirdcircuit in a second circuitry at a different time. Additional examplesof these components with respect to the device 300 follow.

In some aspects, the device 300 may operate as a standalone device ormay be connected (e.g., networked) to other devices. In a networkeddeployment, the communication device 300 may operate in the capacity ofa server communication device, a client communication device, or both inserver-client network environments. In an example, the communicationdevice 300 may act as a peer communication device in a peer-to-peer(P2P) (or other distributed) network environment. The communicationdevice 300 may be a UE, eNB, PC, a tablet PC, an STB, a PDA, a mobiletelephone, a smartphone, a web appliance, a network router, switch orbridge, or any communication device capable of executing instructions(sequential or otherwise) that specify actions to be taken by thatcommunication device. Further, while only a single communication deviceis illustrated, the term “communication device” shall also be taken toinclude any collection of communication devices that individually orjointly execute a set (or multiple sets) of instructions to perform anyone or more of the methodologies discussed herein, such as cloudcomputing, software as a service (SaaS), and other computer clusterconfigurations.

Examples, as described herein, may include, or may operate on, logic ora number of components, modules, or mechanisms. Modules are tangibleentities (e.g., hardware) capable of performing specified operations andmay be configured or arranged in a certain manner. In an example,circuits may be arranged (e.g., internally or with respect to externalentities such as other circuits) in a specified manner as a module. Inan example, the whole or part of one or more computer systems (e.g., astandalone, client, or server computer system) or one or more hardwareprocessors may be configured by firmware or software (e.g.,instructions, an application portion, or an application) as a modulethat operates to perform specified operations. In an example, thesoftware may reside on a communication device-readable medium. In anexample, the software, when executed by the underlying hardware of themodule, causes the hardware to perform the specified operations.

Accordingly, the term “module” is understood to encompass a tangibleentity, be that an entity that is physically constructed, specificallyconfigured (e.g., hardwired), or temporarily (e.g., transitorily)configured (e.g., programmed) to operate in a specified manner or toperform part or all of any operation described herein. Consideringexamples in which modules are temporarily configured, each of themodules need not be instantiated at any one moment in time. For example,where the modules comprise a general-purpose hardware processorconfigured using the software, the general-purpose hardware processormay be configured as respective different modules at different times.The software may accordingly configure a hardware processor, forexample, to constitute a particular module at one instance of time andto constitute a different module at a different instance of time.

The communication device (e.g., UE) 300 may include a hardware processor302 (e.g., a central processing unit (CPU), a graphics processing unit(GPU), a hardware processor core, or any combination thereof), a mainmemory 304, a static memory 306, and mass storage 307 (e.g., hard drive,tape drive, flash storage, or other block or storage devices), some orall of which may communicate with each other via an interlink (e.g.,bus) 308.

The communication device 300 may further include a display device 310,an alphanumeric input device 312 (e.g., a keyboard), and a userinterface (UI) navigation device 314 (e.g., a mouse). In an example, thedisplay device 310, input device 312, and UI navigation device 314 maybe a touchscreen display. The communication device 300 may additionallyinclude a signal generation device 318 (e.g., a speaker), a networkinterface device 320, and one or more sensors 321, such as a globalpositioning system (GPS) sensor, compass, accelerometer, or anothersensor. The communication device 300 may include an output controller328, such as a serial (e.g., universal serial bus (USB), parallel, orother wired or wireless (e.g., infrared (IR), near field communication(NFC), etc.) connection to communicate or control one or more peripheraldevices (e.g., a printer, card reader, etc.).

The storage device 307 may include a communication device-readablemedium 322, on which is stored one or more sets of data structures orinstructions 324 (e.g., software) embodying or utilized by any one ormore of the techniques or functions described herein. In some aspects,registers of the processor 302, the main memory 304, the static memory306, and/or the mass storage 307 may be, or include (completely or atleast partially), the device-readable medium 322, on which is stored theone or more sets of data structures or instructions 324, embodying orutilized by any one or more of the techniques or functions describedherein. In an example, one or any combination of the hardware processor302, the main memory 304, the static memory 306, or the mass storage 316may constitute the device-readable medium 322.

As used herein, the term “device-readable medium” is interchangeablewith “computer-readable medium” or “machine-readable medium”. While thecommunication device-readable medium 322 is illustrated as a singlemedium, the term “communication device-readable medium” may include asingle medium or multiple media (e.g., a centralized or distributeddatabase, and/or associated caches and servers) configured to store theone or more instructions 324. The term “communication device-readablemedium” is inclusive of the terms “machine-readable medium” or“computer-readable medium”, and may include any medium that is capableof storing, encoding, or carrying instructions (e.g., instructions 324)for execution by the communication device 300 and that cause thecommunication device 300 to perform any one or more of the techniques ofthe present disclosure, or that is capable of storing, encoding orcarrying data structures used by or associated with such instructions.Non-limiting communication device-readable medium examples may includesolid-state memories and optical and magnetic media. Specific examplesof communication device-readable media may include non-volatile memory,such as semiconductor memory devices (e.g., Electrically ProgrammableRead-Only Memory (EPROM), Electrically Erasable Programmable Read-OnlyMemory (EEPROM)) and flash memory devices; magnetic disks, such asinternal hard disks and removable disks; magneto-optical disks; RandomAccess Memory (RAM); and CD-ROM and DVD-ROM disks. In some examples,communication device-readable media may include non-transitorycommunication device-readable media. In some examples, communicationdevice-readable media may include communication device-readable mediathat is not a transitory propagating signal.

The instructions 324 may further be transmitted or received over acommunications network 326 using a transmission medium via the networkinterface device 320 utilizing any one of a number of transferprotocols. In an example, the network interface device 320 may includeone or more physical jacks (e.g., Ethernet, coaxial, or phone jacks) orone or more antennas to connect to the communications network 326. In anexample, the network interface device 320 may include a plurality ofantennas to wirelessly communicate using at least one ofsingle-input-multiple-output (SIMO), MIMO, ormultiple-input-single-output (MISO) techniques. In some examples, thenetwork interface device 320 may wirelessly communicate using MultipleUser MIMO techniques.

The term “transmission medium” shall be taken to include any intangiblemedium that is capable of storing, encoding, or carrying instructionsfor execution by the communication device 300, and includes digital oranalog communications signals or another intangible medium to facilitatecommunication of such software. In this regard, a transmission medium inthe context of this disclosure is a device-readable medium.

Although an aspect has been described with reference to specificexemplary aspects, it will be evident that various modifications andchanges may be made to these aspects without departing from the broaderscope of the present disclosure. Accordingly, the specification anddrawings are to be regarded in an illustrative rather than a restrictivesense. This Detailed Description, therefore, is not to be taken in alimiting sense, and the scope of various aspects is defined only by theappended claims, along with the full range of equivalents to which suchclaims are entitled.

What is claimed is:
 1. An apparatus to be used in a user equipment (UE),the apparatus comprising: processing circuitry, wherein to configure theUE for reporting on Reference Signal Time Difference (RSTD)-based 5G-NewRadio (NR) positioning, the processing circuitry is to: determine afirst positioning reference signal (PRS) bandwidth (BW) associated witha first PRS received from a first Next Generation Node-B (gNB), thefirst gNB associated with a first cell; determine a second PRS BWassociated with a second PRS received from a second gNB, the second gNBassociated with a second cell; determine an RSTD report resolution basedon the first PRS BW and the second PRS BW; measure a receive (Rx) timingdifference between the first cell and the second cell based on receptiontimes of the first PRS and the second PRS; and map the measured Rxtiming difference into an RSTD report for transmission to the first gNB,based on the RSTD report resolution; and a memory coupled to theprocessing circuitry and configured to store the first PRS BW and thesecond PRS BW.
 2. The apparatus of claim 1, wherein the processingcircuitry is to: determine the RSTD report resolution based on a minimalPRS BW selected from the first PRS BW and the second PRS BW.
 3. Theapparatus of claim 2, wherein the processing circuitry is to: determinethe RSTD report resolution to be one of a reference timing unit (Ts) ora multiple of a minimal timing unit (Tc) based on a comparison of theminimal PRS BW with a pre-configured threshold value.
 4. The apparatusof claim 3, wherein T_(s)=1/(Δf_(ref)·N_(f,ref))=32.5 ns, and whereinΔf_(ref)=15·10³ Hz and N_(f,ref)=2048.
 5. The apparatus of claim 3,wherein T_(c)=1/(Δf_(max)·N_(f))=0.5 ns, and wherein Δf_(max)=480·10³ Hzand N_(f)=4096.
 6. The apparatus of claim 2, wherein the processingcircuitry is to: determine the RSTD report resolution as${\left( \frac{400\mspace{14mu}{MHz}}{{BW}_{PRS}} \right) \cdot \frac{T_{c}}{2}},$wherein T_(c)=0.5 ns, and wherein BW_(PRS) is selected based on theminimal PRS BW.
 7. The apparatus of claim 6, wherein the BW_(PRS) is abandwidth selected from a set of [5, 10, 20, 25, 40, 50, 80, 100, 200,400] MHz and is closest to the minimal PRS BW.
 8. The apparatus of claim2, wherein the processing circuitry is to: determine the RSTD reportresolution as${\left( \frac{400\mspace{14mu}{MHz}}{BW_{PRS}} \right) \cdot T_{c}},$wherein T_(c)=0.5 ns and BW_(PRS) is selected based on the minimal PRSBW.
 9. The apparatus of claim 8, wherein the BW_(PRS) is a bandwidthselected from a set of [5, 10, 20, 25, 40, 50, 80, 100, 200, 400] MHzand is closest to the minimal PRS BW.
 10. The apparatus of claim 1,further comprising transceiver circuitry coupled to the processingcircuitry; and, one or more antennas coupled to the transceivercircuitry.
 11. A non-transitory computer-readable storage medium thatstores instructions for execution by one or more processors of a userequipment (UE), the instructions to configure the UE for ReferenceSignal Time Difference (RSTD)-based 5G-New Radio (NR) positioning, andto cause the UE to: determine a first positioning reference signal (PRS)bandwidth (BW) associated with a first PRS received from a first NextGeneration Node-B (gNB), the first gNB associated with a first cell;determine a second PRS BW associated with a second PRS received from asecond gNB, the second gNB associated with a second cell; determine anRSTD report resolution based on the first PRS BW and the second PRS BW;measure a receive (Rx) timing difference between the first cell and thesecond cell based on reception times of the first PRS and the secondPRS; and map the measured Rx timing difference into an RSTD report fortransmission to the first gNB, based on the RSTD report resolution. 12.The computer-readable storage medium of claim 11, wherein executing theinstructions further configures the UE to: determine the RSTD reportresolution based on a minimal PRS BW selected from the first PRS BW andthe second PRS BW.
 13. The computer-readable storage medium of claim 12,wherein executing the instructions further configures the UE to:determine the RSTD report resolution to be one of a reference timingunit (Ts) or a multiple of a minimal timing unit (Tc) based on acomparison of the minimal PRS BW with a pre-configured threshold value.14. The computer-readable storage medium of claim 13, whereinT_(s)=1/(Δf_(ref)·N_(f,ref))=32.5 ns, and wherein Δf_(ref)=15·10³ Hz andN_(f,ref)=2048.
 15. The computer-readable storage medium of claim 13,wherein T_(c)=1/(Δf_(max)·N_(f))=0.5 ns, and wherein Δf_(max)=480·10³ Hzand N_(f)=4096.
 16. The computer-readable storage medium of claim 12,wherein executing the instructions further configures the UE to:determine the RSTD report resolution as${\left( \frac{400\mspace{14mu}{MHz}}{{BW}_{PRS}} \right) \cdot \frac{T_{c}}{2}},$wherein T_(c)=0.5 ns, and wherein BW_(PRS) is selected based on theminimal PRS BW.
 17. The computer-readable storage medium of claim 16,wherein the BW_(PRS) is a bandwidth selected from a set of [5, 10, 20,25, 40, 50, 80, 100, 200, 400] MHz and is closest to the minimal PRS BW.18. The computer-readable storage medium of claim 12, wherein executingthe instructions further configures the UE to: determine the RSTD reportresolution as${\left( \frac{400\mspace{14mu}{MHz}}{BW_{PRS}} \right) \cdot T_{c}},$wherein T_(c)=0.5 ns and BW_(PRS) is the selected based on the minimalPRS BW, wherein the BW_(PRS) is a bandwidth selected from a set of [5,10, 20, 25, 40, 50, 80, 100, 200, 400] MHz and is closest to the minimalPRS BW.